Justification:
This newly split species is listed as Vulnerable because, although it appears to be stable, it has a very small population, occupying a very small range on only one island when breeding, and is susceptible to human impacts, including introduced species and stochastic events.

Pterodroma deserta breeds on Bugio in the Desertas off Madeira, Portugal. Based on surveys in 2006-2007, 120-150 pairs breed on Bugio (a lower figure than previous estimates of 150-180 from 2001), but the population appears stable (Ramirez 2008). A recently published study has cast light on the species’s non-breeding distribution, with 17 tracked individuals remaining in the North Atlantic during the pre-laying exodus, incubation and check-rearing periods, and wintering in five areas: two off the Brazilian coast, one around the Cape Verde archipelago, one off the south-eastern coast of the USA, and one in pelagic waters in the central South Atlantic (Ramírez et al. 2013).

Surveys in 2006-2007 suggest that 120-150 pairs breed on Bugio (Ramirez 2008). Based on these data, the population is placed in the band for 250-999 mature individuals, assumed to equate to c.350-1,500 individuals in total.

The species breeds at 80-300 m, usually in burrows excavated in the soil, although recently nests were found in rock crevices in areas were soil is not present(D. Menezes and P. Oliveira in litt. 2007). Birds return to their breeding grounds in early June and juveniles fledge throughout December (D. Menezes and P. Oliveira in litt. 2007.

Historically, the species and its breeding sites have been affected by habitat degradation caused by introduced goats, rabbits and mice (D. Menezes and P. Oliveira in litt. 2007). However, rabbits and mice have been controlled since 2006 (D. Menezes and P. Oliveira in litt. 2007) and goats are reported to only rarely visit the plateau where the breeding sites are located on Bugio (Ramirez 2008). Predation and disturbance by Yellow-legged Gulls Larus cachinnans are potential threats on Bugio. Despite mitigation work, soil erosion at nesting areas remains a threat (J. Sultana in litt. 2013, I. Ramirez in litt. 2014), with extreme weather events, especially in winter, having the potential for major impacts on the areas of soil used for nesting burrows (I. Ramirez in litt. 2014).

Conservation Actions UnderwayA European action plan was published in 1996 (Zino et al. 1996) and its implementation reviewed in 2010 (Barov and Derhé 2011). Since 2006, an eradication programme for rabbits and mice has been in force, and is on-going. As a result, their effect on the most sensitive areas is already negligible. A contingency plan for accidental introductions of invasive species is being developed. A goat eradication programme is on-going and not yet complete. The threat from L. cachinnans is being monitored (D. Menezes and P. Oliveira in litt. 2007). Natural vegetation has been replanted, anti-erosion blankets installed, wardening and monitoring conducted and artificial burrows installed on Bugio as part of a LIFE Nature project (Menezes 2007; Menezes et al. 2011). Geolocators were attached to some individuals from 2007 to investigate foraging ecology (Ramirez 2008). Monitoring of the species is carried out by staff from the Madeiran Natural Park and other researchers, although such work requires great efforts, as the southern plateau of Bugio is extremely remote (I. Ramirez in litt. 2014).

Conservation Actions ProposedConduct coordinated surveys to obtain an up-to-date estimate for the total breeding population. Continue annual surveys to monitor population trends. Study the at-sea distribution of the species. Complete control measures against goats. Continue control measures against rabbits and mice. Assess the impact of L. cachinnans through detailed research.

Citation:

BirdLife International 2014. Pterodroma deserta. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 02 August 2015.